Regulatable feeding apparatus



Oct. 15,1929. L. v. ANDREWS ET AL 1 ,731,

REGULATABLE FEEDING APPARATUS Filed March 29, 1926 F lII/IIII/IIIIIIIIIIIII I I I'- 1 V 7/ II, III III/III III/II 4 INVENTORS WITNESSES r L. V. ANDREWS Q.,& ULLISON CRAIG MN r 7 BY Q ATORNEY Patented Oct. 15, 1929 UNITED STATES PATENT OFFICE L. V. ANDREWS AND OLLISON CRAIG, 0F WORCESTER, MASSACHUSETTS, ASSIGNORS TO RILEY STOKER CORPORATION, OF WORCESTER, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS REGULATABLE FEEDING APPARATUS Application filed. March 29, 1926.

This invention relates to feeding devices and more particularly to an apparatus capable of feeding material, such as coal, at aregulatable and uniform rate.

In order to burn pulverized coal efficiently, it is necessary that the coal be fed to the burner continuously and at a predetermined rate, and that the rate of feed be varied as determined by the load on the boiler. In accordance with the usual practice, the coal is either pulverized initially and then stored in a bin from which it is fed to the furnace, or it is fed directly in a lump or semi-broken form to a pulverizer and from there blown directly into the furnace. If for any reason the fuel feed to the furnace stops, then the flame necessarily goes out and the oper ation of the furnace is seriously affected. Moreover, the moisture content of coal, as well as other physical characteristics, does not remain uniform, and such variations affect the rate at which the material will feed.

It is accordingly desirable that the rate of feed be easily regulatable and that, if the feed is regulated automatically, there should be manually adjustablefeatures which permit one to vary the feed at will, so as to insure a uniform and continuous feeding These considerations apply generally to many materials which are to be fed continuously in measured amount. Also, there is a need for an apparatus which is capable of feeding numerous types of material at regulatable'rates.

It is the main object of our invention to provide a'simple and efficient feeding apparatus which satisfies these various requirements and whlch is capable of feeding coal or other 7 material ataregulatable and substantially uniform rate and insuring that the material will be fed continuously and without inter- ;ruption during normal usage of the apparatus. I

It is a further object of our invention to provide a feeding apparatus which may be automatically regulated to give a desired rate of feed but which may be adjusted manually to'vary the rate ofautomatic' feed,,and which is so. constructed and arranged as to require the minimum of attention on the part of the operator.

action.-

Serial No. 88,100.

WVith these and other objects in view as will be apparent in the following disclosure, our invention resides in the combination of parts set forth in-the specification and covered by the claims appended hereto.

Referring to the drawings in which like reference numerals indicate like parts:

Fig. 1 is a top plan view of one embodiment of our invention with parts shown in substantially horizontal section;

Fig. 2 is a vertical section substantially on the line 2-2 of Fig. 1; and

Fig. 3 is a detail in elevation of the lower portion of the hopper and the adjustable lineiibers which determine the amount of fuel In accordance with our invention, we provide a feeding apparatus which comprises a horizontal table rotatable about a vertical axis and a hopper mounted above the table and arranged to present material thereto. A scraper is mounted above the table to sweep material therefrom, and is adjustable to vary the feeding rate. The hopper is preferably.

tated slowly by means of a worm gear 16 suitably fixed thereon and driven by a worm 17 rotated by any suitable power driven mechanism. The top portion 18 of the casing forming a cover has a central opening therethrough communicating with a hopper 20 mounted on the casing. A flange 21 forms the lower half of the hopper and is suitably fastened to and depends from the cover 18 to a position close to the table. The lower portion 21 of the hopper is cut away at 24; to form an opening through the side thereof so that material in the hopper may escape outwardly through this opening and fall over the edge'ofthe table. The table as will be observed has a much greater diameter than that of the hopper so as to form an outer, annular portion on which the material may ride in repose after it has escaped through the opening 24:.

Since the materials which may be fed by this apparatus vary in their physical characteristics, and their angles of repose will not be the same, we provide a positively acting mechanism for cutting a certain amount of material from the hopper and scraping it off the annular portion of the table as the latter revolves. This comprises a scraper or knife 25 which is adjustably supported in substantial contact with the top fiat surface of the table and projects inwardly through the opening 24. The outer portion of the scraper projects over the edge of the table adjacent the upper end 26 of a chute through which the material is to be fed to other apparatus or to a storage bin.

In the course of our experimentation we have found that the operative surface of this scraper 25 should have a definite angular relation to the direction of travel of the moving material on the rotating table, and that this angular relation should not change as the knife is adjusted into different positions. If the scraper extended radially towards the center of the table, then it would merely serve as an obstruction to the moving material and would not scrape the same from the table. Hence we propose to have this scraper arranged with its operative surface in a non-radial position and preferably at an acute angle to the line of travel ol the material, which is indicated by the arrow in Fig. 1, and we propose to move this scraper in such a manner that this angle will remain substantially the same as the position of the scraper is adjusted. Hence, whether a small or a large amount of material is fed, the action of the knife is the same, so that the amount ol material ted 01 3 the table bears a definite relation to the location of the scraper, and there will be no greater tendency for wet material topile up against the scraper one position of adjustment than at another.

In order to accomplish this, we prefer to mount the scraper in such a manner that it i may be moved always parallel with itself,

guided easily and it carries depending from it the scraper 25 as clearly illustrated in the drawings. The shaft 30 is arranged to be rotated suit-ably such as, by means of a hand wheel 36. Stops 37 and 38 are provided on the casing so as to limit the longitudinal movement of the nut which carries the scraper. v

As illustrated, the device may be operated by means of a power actuateddevice, such as a hydraulic motor. This construction comprises a 'rod 40 slidably mounted in the,

flanges 41 and a2 projecting from the casing. The rod is adapted to be connected by a collar 43 fixed thereon to a suitable power mechanism capable of reciprocating the rod as desired, which. is diagrammatically illustrated as a hydraulic motor 44, arranged to be controlled by a steam pressure regulator or by any other suitable device. This slide rod 40 has an arm 45 pinned thereto and the outer end of this arm has an opening through which the screw threaded shaft 30 passes. This shaft 30 is rotatably fixed to the arm 45 by means of two collars 46 which permit the shaft to rotate but cause it to slide longitudinally with the shaft 40 In order that the shaft 30 may slide, the bearings 31 and 32 are formed merely as stationary concentric sleeves. g

If it is desired to move the scraper 25 manually without automatic regulation, the set screw 48 in the flange 42 is screwed into a groove in the rod l0 so as to locate the rod properly and cause it to be held stationary, thereby making it possible to turn the hand wheel 36 and rotate the screw without mov ing the rod 40. Wheat-he rod 40 is held stationary, then the hand wheel 36 is the sole device for moving the scraper 25, but if the automatic features are to be employed, the rod 40 will move the scraperas it is moved by the automatic regulator, and the huntwheel 36 serves solely as an adjustment device adapted to position the scraper 25 adjusta'oly relative to the rod 40, thereby changing its positionwith reference tothe regulating device.

The height of. the opening Ell is determined by the angle of repose of the material.

to be fed, itbeing necessary that theopening be or such height, or conversely that the table extend to such a distance beyond the hopper, that the material will not fall off the table without tnejaid of the knife. Also, the opening 2 2 is of considerable length seas to insure lumps of coal escaping from the opening and not clogging it. Thescraper is made in a triangular shape, as illustrated, with its narrow portion pro ecting into the hopper and much lower than the height of the opening 24. This arrangement is such that if a large lump of coal strikes the point of the scraper it may either be sent out through the opening 24 and oil the table or it may ride up over the scraper and come around again for another try, but it is not likely to wedge between the scraperand the and make it impossible for material to wedge in the rear of the scraperand between it and the hopper flange. This slide is made arcuate 111 shape, as shown in Fig. 1, so as to fit the outer periphery of thecylindrical flange 21. In order to move the slide to keep the opening in the rear of the scraper 25closed, we provide a linlr 52 pivotally connected at one end to the slide 50 and at the other end to the nut 35.v These parts are so shaped and arranged that as the scraper 25 moves outwardly, the shde 00 fol lows along in the rear and as the scraper moves inwardly the slide retreats to make room for it. A cap screw 58 fixed to the hopper projects through a slot 54: in the slide and the head of the screw serves to hold the slide in position against the hopper.

There is a considerable difference between the various materials which may be fed inthis device, as well as their behavior under different climatic conditions. If coal is being fed and the apparatus is set so that it will feed, sa 3000 lbs. per hour as indicated by the pointer 55' connected with the nut 35 and moving over the index scale 56, and if the fuel should later become wet due to a rain storm, the coal would tend to pile up is shaped to lit the outer periphery of the flange 21, as shown partlculariy in Fig. l,

and the lower front edge of this gate is beveled as shown at 59 in Fig. 8. The gate may be manually ad usted by suitable mechanism, which comprises a shaft 60 rotatably mounted in bearings 61 and 62 and prevented from endwis-e movement by collars 68 and 64. The shaft 60 is threaded between the bearings (51 and 62 and a screw threaded nut 65 is mounted thereon and connected by a link'66 pivotally connected to the gate 58. A hand wheel 67 serves to rotate the shaft. 58 may be held in position by means of a cap screw 68 projecting outwardly from the hopper flange through a slot 69 in the gate and having an enlarged head which prevents the slide from being pulled away from the flange. f

In order to agitate the material in th hopper, we provide an extension 70 threaded on to the end of the shaft 13-above the table 12. A rod 71 passes through the extension An adjustable The gate- 70 and is fixed therein, and two plates 72 are riveted around these parts and suitably connected thereto, so as to form an extensive agitating surface capable of moving the coal around in the hopper as the table 12 revolves. The parts 71 and 72 are shown at right angles to eachother in Figs. 1 and 2 for the sake of. clearness of illustration.

' The operation of this device will now be apparent from the above disclosure. Coal or other material that is to be fed by means of this apparatus is fed into the hopper 20 and is caused to pile up on the table 12 and be revolved by means of the agitating devices and the table. The scraper 25 is suitably adjusted as determined by experience so that it projects within the opening 24 of the hopper flange 21 the desired distance. As the table revolves, the scraper 25 sweeps oil the outer layer of material in contact there with. The remainder of the material above the scraper escapes over'the top of the scraper and is held within the'hopper by the sleeve 50. If the device is connected through the collar 43 with a steam regulator device or other suitable type of furnace regulator, then the scraper will be moved back and forth parallel with itself, as determined by the load onthe boiler and the requirements imposed on the feeding apparatus, and so scrape oil the right amount of fuel. By adjusting the hand wheel 86, the blade 25 may be suitably positioned relative to the rod 40, whereby the rate of feed as determined by the power actuated mechanism may be manually varied. By turning the hand wheel 67 on the shaft '60, the gate 58 may be moved back or forth I'laving' thus described our invention, what we claimas new and desire to secure by Letters Patent, is I i I 1. A feeding device comprising a rotary table,a hopper disposed above and close to the table and arranged to present material thereto, said hopper having an opening in one side, a scraper having its lower edge disposed substantially in contact with the table'and proj ecting inwardly through said opening; to scrape material from the table, the upper edge of said scraper tapering downwardly towards the lnner end to form substantially a point adjacent to the surface of the table and being so arranged relative to the opening in the hopper that the coarse lumps of material will not obstruct the opening.

. 2. A feeding device comprising a rotary table, a hopper thereabove having an opening in oneside to present material to the table and permit its escape a scraper adjustably arranged in said opening over the table to scrape material therefrom, means to move said scraper back and forth to regulate-the amount of feed, and a slide in the rear of the, scraper arranged to close the back opening between the scraper and the hopper.

3. A feeding device comprising a rotary table, a hopper above the table and arranged to present material thereto, said hopper having an opening in one side, a scraper projecting inwardly through said opening and being so constructed and arranged that it will scrape material from the table through the opening, means to move the scraper back and forth in order to regulate the feed, and a movable gate arranged to vary the opening in ad- Vance of the scraper which permits further manual adjustment of the rate of feed.

4. A feeding device comprising a horizontal disk shaped table adapted for rotation about a vertical axis, means to rotate said table, a hopper arranged above the table and close to its upper surface, said hopper being of smaller diameter than the table and having an opening through one side of such height relative to the width of the annular portion of the table outside of the hopper that material in normal repose will be held on the table, and an adjustable scraper having its lower edge close to the table and extending across said annular portion in such a way as to sweep material at a desired rate from the table as the latter rotates.

5. A feeding device comprising a horizontal, flat, disk shaped table, means to rotate the same about a vertical axis, a hopper arranged above and close to the table to present material thereto, said hopper being of smaller diameter than the table and having an opening through one side of such height relative to the width of the annular portion of the table outside of the hopper that material in normal repose will not fall off the table, an adjustable scraper having its lower edge close to the table and extending across said annular portion adjacent the hopper opening at an acute angle to the path of travel of the rotating table, which'is arranged to sweep a desired amount of material therefrom as the table rotates, and means tomove the scraper parallel with itself to regulate the amount of material fed thereby.

6. A feeding device comprising a hopper for material to be fed, means for feeding the material at a uniform ratefrom said hopper, a power actuated mechanism for adjusting said feeding means, and a manually operated device for varying the rate of feed corresponding to any given position of the power actuated mechanism.

7. A feeding device comprising a rotatable table, means to rotate said table, a hopper arranged above the table to present material thereto, an adjustable member mounted above the table to regulate the rate of flow of the material from said table, and a power actuated device to move said adjustable member and thereby vary the rate of feed.

8. A feeding device comprising a tablev adapted for rotation about a vertical axis, means to rotate said table, a hopper arranged above the table to present material thereto, an adjustable scraper mounted above the table to sweep material from said table ata desired rate as the table rotates, and a power actuated device to move the scraper and thereby vary the rate of feed.

9. A feeding device comprising a rotary table, a hopper having an opening in one side arranged to present material to the table, a scraper adjustably mounted to sweep a variable amount of material from the table through said hopper opening, power actuated mechanism to move the scraper and vary the rate of feed, and a manually adjustable device to change the position of the scraper relative to the power actuated mechanism.

10. A feeding device comprising a table rotatable about a vertical axis, means to rotate said table, a hopper arranged above the table to present material thereto, an adjustable scraper mounted adjacent the top surface of the table to sweep material therefrom, a

hydraulic motor connected to said scraper to control the position thereof, and manually operable means to vary the relation of said scraper to said hydraulic motor.

11. A feeding device comprising a horizontal disk shaped table rotatable about a vertical axis, a hopper mounted above the table and arranged to present material thereto, a scraper mounted close to the upper surface of the table and having an operative surface in a non-radial position arranged to sweep the material continuously from the table, and means for adjusting the scraper parallel with itself to cause its point to travel along a radial line toward the axis of the table and its operative surface adjacent its point to make the same angle with the direction of travel of the material for any position of adjustment of the scraper.

Signed at Worcester, Massachusetts, this 25th day of March, 1926.

' L. V. ANDREXVS.

OLLISON' CRAIG. 

